[Tislelizumab monotherapy for the treatment of recurrent/metastatic head and neck squamous cell carcinoma].

The aim of this retrospective study is to evaluate the safety and efficacy of tislelizumab in patients with recurrent/metastatic head and neck squamous cell carcinoma. Six patients with recurrent/metastatic head and neck squamous cell carcinoma who received tislelizumab monotherapy in our hospital from 2018 to 2020 were retrospectively analyzed. The information of sex, age, TNM stage, efficacy, and adverse reactions were collected. All patients were recruited from the RATIONALE 102 study. The primary end point was the objective response rate, and other end points included progression-free survival and overall survival. We performed tumor immune-related gene sequencing and transcriptome sequencing analysis on the tumor tissues of the patient, and used bioinformatics methods to enrich immune cells and analyze signaling pathways. All analyses were performed using R 4.1. 0 software, SPSS Statistics 24.0 software and GraphPad Prism 8. As of May 31, 2020, the median follow-up time was 26.35 months. The objective response rate with tislelizumab was 50.0%, the median progression-free survival was 6.44 months, and the estimated median survival was 20.07 months. The incidence of grade 3 or higher adverse reactions was 66.7%, including hyponatremia, hypokalemia, hypercalcemia, etc. The expression of macrophage, Treg and neutrophil-related genes are higher in immune-sensitive patients, and the signaling pathways of the intestinal immune network for IgA production, graft versus host disease and autoimmune thyroid disease are significantly activated. Tislelizumab was found to be controllable and tolerable in patients with recurrent/metastatic head and neck squamous cell carcinoma. The response to tislelizumab is related to immune cell infiltration and activation of immune-related signaling pathways.